Hi there Krem!
Cows? Hmm no, the Farm is just area level 81 or so. With a javazon I would probably do the Chaos Sanctuary which is L85... and you probably know I'm too much German to give up efficiency. On the other hand, cows are good at dropping runes for some reason, but I think that finding HRs is mostly a matter of being lucky while looking for something else.
My primary goal is finding that one and only rune/unique/set item I've never found so far: Griffon's. Yes, I've found all the rest, all runes up to Zod, Tyrael's, Mang Song's etc. etc. - some of which is much more rare than this unique diadem. I'm pretty much annoyed about having found M'avinas True Sight, the set diadem, for half a dozen times... I even stopped picking it up!